Si semiconductor detectors with extremely high energy resolution are widely used as a device for measuring α rays in a dust monitor for monitoring plutonium contamination. However, the Si semiconductor detectors have a problem that the electrodes are susceptible to corrosion by moisture in the air. In addition, the Si semiconductor detectors have a problem that the detectors tend to pick up electric noise and provide an erroneous output.
In order to solve the problems of the Si semiconductor detectors described above, Izaki et al., the inventors, have proposed a ZnS(Ag) scintillation detector serving as an α rays measuring apparatus that is filled with a plurality of layers of ZnS(Ag) scintillator particles having a particle diameter of 5 μm having a thickness of 10 mg/cm2, in Japanese Patent No. 4061367 (Patent Literature 1).
There is also a scintillation detector used in a positron emission tomography (PET) apparatus or the like for a nuclear medicine image diagnostic method.
For example, in Japanese Patent Laid-Open No. 2006-199727, there is proposed a radiation detector that uses a scintillator made of a single crystal cerium-activated lanthanoid silicate as an X-rays detector used in a positron emission tomography apparatus (Patent Literature 2).